Peroxide Compounds Research Articles

Cytotoxic Activities of 9,11-Dehydroergosterol Peroxide and Ergosterol Peroxide from the Fermentation Mycelia of Ganoderma lucidum Cultivated in the Medium Containing Leguminous Plants on Hep 3B Cells

The objective of this study was to investigate the cytotoxicity of the ethanolic extract of mycelia from Ganoderma lucidum (EMG) cultivated in a medium containing leguminous plants Glycine max (L.) Merr. and Astragalus membranaceus on human hepatocellular carcinoma cells (Hep 3B) and to isolate the active components from EMG. The results indicated that EMG induced cytotoxicity in a dose- and time-dependent manner, and the cells treated with EMG for 24, 48, and 72 h had IC(50) values of 156.8, 89.9, and 70.1 microg/mL, respectively. Furthermore, EMG was fractionated into seven fractions (F1-F7). We found that F5 and F6 had higher growth inhibitory effects on Hep 3B cells than the other fractions, and F6 possessed enough amounts (about 2.1 g) to carry out a more detailed study. F6 caused a sub-G1 peak rise and DNA fragmentation in Hep 3B cells and was further separated by high-performance liquid chromatography to obtain two active compounds, 9,11-dehydroergosterol peroxide [9(11)-DHEP] (compound 1) and ergosterol peroxide (EP) (compound 2). The IC(50) values of 9(11)-DHEP and EP based on the cell viability of Hep 3B were 16.7 and 19.4 microg/mL, respectively.

Progress in the development of peroxide-based anti-parasitic agents

Progress made in the past decade pertaining to the development of anti-parasitic agents based on artemisinin is presented. Apart from discussions on important derivatives obtained through functionalization at the C-3, C-9, C-10 and O-11 positions of artemisinin, an outline on its seco analogs and artemisinin bundles are given for a broader perspective on structure-activity relationships. Success with synthetic peroxides, drug-hybrid approaches, broad-spectrum anti-infective properties of peroxide compounds and a survey on peroxide-containing natural products other than artemisinin with available biological data are included to highlight recent trends and avenues for future research. A supplementary material with details on the biological properties of a larger collection of molecules belonging to the above structural classes is also given for reference.

Kinetics and mechanism of decomposition of peroxide compounds in the liquid phase of the KOH-H2O2-H2O system in vessels made of various materials

Decomposition kinetics of peroxide compounds in the liquid phase of the system KOH-H2O2-H2O at an initial hydrogen peroxide concentration of about 14.5 M and pH 12.7 in vessels made of Pyrex glass, polyethylene terephthalate, and 12Kh18N10T steel was studied in the temperature range from −10 to +50°C. The main kinetic parameters of the processes under study were determined. The influence exerted by the material of the reaction vessel on the kinetics and mechanism of decomposition of peroxide compounds in the liquid phase of the system under study were determined.

Comparative effect of N-substituted dehydroamino acids and α-tocopherol on rat liver lipid peroxidation activities

Free radical damage has been associated with a growing number of diseases and conditions, such as autoimmune diseases, neurodegenerative disorders and multiple types of cancer. Some dehydroamino acids and corresponding peptides can function as radical scavengers. In this study the in vitro effects on rat liver lipid peroxidation levels of fourteen N-substituted dehydroamino acid derivatives and α-tocopherol were investigated. α-Tocopherol is a powerful antioxidant that is beneficial in the treatment of many free radical related diseases. The results indicated that all the compounds showed very good inhibitory effect on the lipid peroxidation compound with α-tocopherol at 1 mM concentrations and the inhibition rate was in the range of 70–79 % with the exception of compound 5. At 0.1 mM concentrations compounds 1, 2 and 9 were found more active than α-tocopherol. The results confirmed that molecules such as dehydroamino acids which have reactive double bonds can act as a guard in vitro against oxidants.

Efficacy of Some Commercial Chemical Disinfectants on Salmonella enterica Serovar Typhimurium

Problem statement: Poultry industry is intensive and consistently applies an all-in, all-out system with the aim of minimizing infection pressure and targeting specific pathogens like Salmonella which remains one of the leading causes of food-borne illness, many questions regarding the introduction and persistence in animal production still remain. Therefore disinfection during production break is a routine part of the biosecurity programs of poultry houses. The correct usage of disinfectants is an important key of a successful biosecurity program in poultry farms and in-turn the role of the scientist was to evaluate the efficacy of these disinfection programs. Approach: In this study five commercial disinfectants [Green work (green non anionic surfactant), Sanidate RTU (hydrogen peroxide compound), Hi-yeild®consan 20® (phenolic compound), Tektrol® (quaternary ammonium compound) and Kreso®D (phenolic compound)] were evaluated against Salmonella typhimurium in two different experimental conditions. In Experiment I, S. typhimurium was inoculated into fresh poultry litter (aluminum trays L: 30 cm × W: 25 cm × D: 6 cm filled with wood shavings) by inoculums size of ~107 CFU mL-1 and then mixed with 100 g of fresh poultry droppings. Sample sizes of 3 g were obtained daily for the bacterial counts. Green work achieved100% killing of S. typhimurium by day 7 (p≤0.0001); Sanidate RTU achieved100% killing by day 6 (p≤0.001); Hi-yield® Consan®, Tektrol® and Kreso® D achieved100% killing by day 5 (p≤0.001). Disinfectants were also compared to each other in their efficacy each day. At day 1, Green work was inferior to all other disinfectants at (p≤0.05). On day 2, Kreso® D was significantly superior to Tektrol®, Hi-yield® Consan®, Sanidate RTU and Green work at p≤0.01, p≤0.01, p≤0.01, p≤0.005; respectively. At day 4 Kreso® D was significantly superior to Hiyield ® Consan® at p≤0.01, Tektrol® was also significantly superior to Green work at p≤0.01. In experiment II; MIC use-dilution test was used to evaluate the five disinfectants against S. typhimurium (~107CFU mL-1) in the absence of organic matter. Results: Hourly samples were collected for the bacterial counts. Maximum efficacy (100% killing efficacy against S. typhimurium) was achieved for Green Work after 16 h (p≤0.0001), with Sanidate RTU after 8 h (p≤0.0001), with Hi-yield® Consan® and Kreso® D after 2 h at (p≤0.0001) and with Tektrol® after 4 h (p≤0.0001). In presence of organic matter Green work and Sanidate RTUachieved 100% killing efficacy against S. typhimurium after 16 h (p≤0.0001), Hi-yield® Consan® and Kreso® D after 2 h at (p≤0.0001); Tektrol® after 8 h (p≤0.0001). When disinfectants were compared to each other in relation to time; we found that there was no kind of significance between their efficacies. When compared to other tested disinfectants, Kreso® D which is a phenolic compound revealed superior activity against Salmonella typhimurium in the two experiments. Conclusion: The study showed that many disinfectants regardless to their constituents continues to give a very powerful efficacy against the most virulent bacterial strains, but the question remain can they be used in the presence of live birds. Further studies are required to explore the safety and the efficacy of these compounds when applied in poultry farms in the presence of live birds.

Isolation and Identification of Lactic Acid Bacteria Inhibiting the Proliferation of Propionibacterium acnes and Staphylococcus epidermidis

Propionibacterium acnes is the most common causative agent of acne. Staphylococcus epidermidis is another major bacterial strain to be found in acne lesions. Two strains of lactic acid bacteria (LAB) were isolated from normal inhabitants of humans, which inhibited the proliferation of P. acnes and S. epidermidis. The growth of P. acnes and S. epidermidis was decreased by 4-log scales after incubation for 24 h with LAB isolates, whereas the growth rate of selected LAB isolates were not affected by these pathogenic bacteria. This antibacterial activity of LAB isolates was related to lactic acids, hydrogen peroxide and bacteriocin-like compound production. Two LAB isolates efficiently adhered to human keratinocytes HaCaT and were identified by API 50 CHL medium kit and 16S rDNA partial sequencing analysis. The similarity of 16S rDNA sequences between one isolate and Lactobacillus salivarius subsp. salicinius was 100%, which suggests that they were L. salivarius subsp. salicinius. On the other hand, 16S rDNA sequence similarity between the other isolate and Lactobacillus fermentum was 99.04%, which indicates that it was L. fermentum. In conclusion, these results demonstrate that the two LAB strains isolated from human body were identified as L. salivarius subsp. salicinius and L. fermentum, which inhibit the proliferation of P. acnes and S. epidermidis.

Electrochemical biosensors based on horseradish peroxidase

The principles used for the development of electrochemical biosensors based on horseradish peroxidase are described. Peroxidase is the enzyme which catalyses the oxidation of a variety of organic molecules in the presence of hydrogen peroxide. The features of this enzyme are high catalytic activity and low specificity towards second substrate as well. Horseradish peroxidase may be used as a component of active part of biosensors for the detection of hydrogen peroxide and other compounds when peroxidase is co-immobilized together with other oxidases. Also horseradish peroxidase may be used as a component of detecting system for the biosensors based on biological recognition using specific antibodies, receptors, nucleic acids. The examples of the bio-, immuno-, DNA-sensors developed for the determination of various biologically active compounds are given.

In Vitro Effect of Oxidized Dextrans on Peritoneal Cells

We studied the dependence of in vitro dextran biocompatibility on the method of oxidation of 35-kDa dextran. The biocompatibility of dextran oxidized with potassium permanganate was higher compared to that obtained by radiochemical oxidation. It was related to the formation of peroxide compounds during radiochemical oxidation.

Factors associated with changing efficacy of emamectin benzoate against infestations of Lepeophtheirus salmonis on Scottish salmon farms

The availability and use of medicines to control infestations of sea lice on Atlantic salmon, Salmosalar L., farms in Scotland has changed considerably in the last decade (Lees, Gettinby & Revie 2008b). Whereas hydrogen peroxide and organophosphate compounds were used widely throughout the 1990s and in the early 2000s, only two therapeutants have remained in common use since 2005: topical cypermethrin (Excis; Novartis Animal Health, Camberley, UK) and an oral formulation of emamectin benzoate (SLICE; Schering Plough Animal Health, Uxbridge, UK).

The use of magnesium peroxide for the inhibition of sulfate-reducing bacteria under anoxic conditions

Sulfate-reducing bacteria (SRB), which cause microbiologically influenced material corrosion under anoxic conditions, form one of the major groups of microorganisms responsible for the generation of hydrogen sulfide. In this study, which is aimed at reducing the presence of SRB, a novel alternative approach involving the addition of magnesium peroxide (MgO2) compounds involving the use of reagent-grade MgO2 and a commercial product (ORC) was evaluated as a means of inhibiting SRB in laboratory batch columns. Different concentrations of MgO2 were added in the columns when black sulfide sediment had appeared in the columns. The experimental results showed that MgO2 is able to inhibit biogenic sulfide. The number of SRB, the sulfide concentration and the sulfate reducing rate (SRR) were decreased. ORCtrade mark as an additive was able to decrease more effectively the concentration of sulfide in water and the SRB-control effect was maintained over a longer time period when ORCtrade mark was used. The level of oxidation-reduction potential (ORP), which has a linear relationship to the sulfide/sulfate ratio, is a good indicator of SRB activity. As determined by fluorescence in-situ hybridization (FISH), most SRB growth was inhibited under increasing amounts of added MgO2. The concentration of sulfide reflected the abundance of the SRB. Utilization of organic matter greater than the theoretical SRB utilization rate indicated that facultative heterotrophs became dominant after MgO2 was added. The results of this study could supply the useful information for further study on evaluating the solution to biocorrosion problems in practical situations.

N,N,N�N�-tetraacetyletylenedyamine (TAED) as an Activator for Persodiums, in Modern Compositions of Detergents and Disinfectants

The synthesis of N,N,N�,N��tetraacetylethylenediamine (TAED) in two steps was approached, using as a basic raw material ethylenediamine, this one being acetylated in the first step with acetic acid to give N,N��diacetylethylenediamine (DAED), DAED being acetylated afterward with acetic anhydride up to TAED; both steps of the process are accomplished in a xylene medium. The purification of the raw product is made from a mixture of acetic acid and ethanol, giving TAED with a purity that allows it to be used in detergent and disinfectant mixtures. The activation capacity of the peroxidic compounds was tested using sodium percabonate, as a single compound or in a mixture with TAED, on several bacterias.

Dye-sensitized phototransformation of chlorophenols and their subsequent chemiluminescence reactions

A novel chemiluminescence (CL) reaction of chlorophenols (CPs), including 2-chlorophenol (2-CP), 4-CP, 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP) and pentachlorophenol (PCP) was reported, which was based on the oxidation of the phototransformed CPs by N-bromosuccinimide (NBS). It was found that the dye-sensitized phototransformation is a prerequisite for the subsequent CL reaction, and the presence of 1.9×10 –2 mol L −1 Triton X-100 or 3.7×10 –3 mol L −1 CTAB can greatly enhance the CL intensity. A neutral sample solution with the presence of 2×10 –5 mol L −1 fluorescein (FL) was found to be optimum for the phototransformation of 2-CP, 4-CP, 2,4-DCP and PCP, but a lower pH of 5.3 was more suitable for 2,4,6-TCP. Based on the CL reaction, detection limits of 8.6×10 −8, 1.1×10 −7, 1.5×10 –7, 4.6×10 –8 and 3.0×10 −5 mol L −1 were achieved, respectively, for 2-CP, 4-CP, 2,4-DCP, 2,4,6-TCP and PCP with the optimized conditions in the flow system. The mechanism of the phototransformation and the subsequent CL reaction were preliminarily studied and it was suggested that the singlet oxygen formed in the dye-sensitization process was responsible for the conversion of CPs into light-emitting precursors. These intermediate products were suggested to be peroxide compounds after testing by a luminal-based post-column CL detection experiment.

Efficacy and safety of artemether against a natural Fasciola hepatica infection in sheep

Triclabendazole is the current drug of choice against Fasciola spp. infections in livestock, but resistance has become a major problem. In this study, we assessed the efficacy and safety of artemether, a derivative of artemisinin, in sheep with a low natural Fasciola hepatica infection. Artemether was administered orally or intramuscularly; sheep were monitored for 8 h posttreatment and then once daily for adverse events, and drug efficacy was estimated by fecal egg count reductions and worm burden reductions. Single 40- and 80-mg/kg oral doses of artemether showed no effect on F. hepatica egg and worm burden. Treatment with a single 160-mg/kg intramuscular dose of artemether significantly reduced the egg burden (64.9%) and worm burden (91.3%). At half this dose, a worm burden reduction of 65.3% was obtained, which was still statistically significant (P < 0.05). The lowest intramuscular dose of artemether investigated (40 mg/kg) yielded no effect on egg counts and worm burden. There were no adverse events due to artemether; however, two abortions were observed 7 days posttreatment. In conclusion, artemether shows interesting fasciocidal properties in sheep, but embryotoxicity is of concern. Further studies are warranted to assess the potential of additional artemisinin derivatives and other peroxidic compounds for the treatment of Fasciola spp. infections in different ruminants.

State of the antioxidant enzyme complex in tissues of the Black Sea mollusc Mytilus galloprovincialis under natural oxidative stress

The state of the antioxidant (AO) system (AOS) and the content of products of lipid peroxidation (LPO) in hepatopancreas, gill, and foot of the Black Sea mollusc Mytilus galloprovincialis Lam. were studied in norm and under conditions of natural oxidative stress (spawning). It has been established that under conditions of spawning, the AO-protection of hepatopancreas cells is predominantly oriented to inactivation of high concentrations of peroxide compounds with participation of glutathione peroxidase and catalase. In the foot tissue, on the contrary, the main role in AO-processes is played by enzymatic inhibition of superoxide anion radical with aid of superoxide dismutase. The highest level of oxidative stress in the spawning state is revealed in the mollusc gill, which is indicated by the maximal increase of the content of TBA (thiobarbituric acid)-active products.

Reactions of o-cresol with ozone in acetic anhydride

The kinetics of o-cresol oxidation with ozone in acetic anhydride was studied. It was shown that o-cresol was acylated in acetic anhydride to give o-cresyl acetate. Ozone attacks the C=C bonds of the aromatic ring of o-cresyl acetate to give unsaturated peroxide compounds. The composition of the oxidation products alters when the ozonation is carried out in the presence of catalytic amounts of sulfuric acid. Along with the products of the destructive oxidation of the aromatic ring, the methyl group oxidation products appeared as the acyl derivatives o-acetoxybenzyl alcohol and o-acetoxybenzaldehyde, a form that is more stable toward the action of ozone (10%). The addition of manganese(II) acetate to the reaction mixture increases the methyl group oxidation selectivity to 75%. The mechanism of the ozone reaction with o-cresol in acetic anhydride that explains the obtained results is discussed.

Oxidant‐Free Alcohol Dehydrogenation Using a Reusable Hydrotalcite‐Supported Silver Nanoparticle Catalyst

Additive free: Hydrotalcite-supported silver nanoparticles act as a highly efficient heterogeneous catalyst for the dehydrogenation of diverse alcohols (see picture) in the absence of any acceptors such as molecular oxygen, hydrogen peroxide, or unsaturated organic compounds. The solid Ag catalyst was readily reusable without any loss of activity and selectivity. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2008/z703161_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Bactericidal Effect of Several Chemicals on Hatching Eggs Inoculated with Salmonella serovar Typhimurium

Breeder flocks and commercial hatcheries represent an early contamination point for Salmonella entry into commercial integrated poultry operations. Utilizing effective antimicrobial treatments for hatching eggs is a critical part of reducing the incidence of Salmonella-colonized chicks on the farm. The objective of this study was to evaluate the bactericidal effect of several chemicals on Salmonella-contaminated hatching eggs. Four replications (n = 10/treatment per replicate) were conducted to determine the efficacy of 7 commercially available compounds. The compounds tested were as follows: 1) hydrogen peroxide, 2) water-oil emulsion droplets stabilized by detergent, 3) peroxyacetic acid, 4) 4 quaternary ammonium compounds attached to a polymer, 5) 2 quaternary ammonium compounds, 1 biguanide compound and bronopol attached to a polymer, 6) N-alkyl dimethyl benzyl ammonium chloride and stabilized urea, and 7) polyhexamethylenebiguanide hydrochloride. A naladixic acid-resistant Salmonella serovar Typhimurium was inoculated (103 cfu/mL) onto fertile hatching eggs by drip-inoculation. Controls included a positive control (no spray application) and a water control (spray containing water to take into account rinsing effects). Compounds 5 and 7 had a 100% reduction, and both of these chemicals included a biguanide. Compounds 4 and 3 were also effective with a 95 and 93.5% reduction, respectively. Compounds 6 and 2 were the least effective of all chemicals, with a reduction of 47.5 and 40%, respectively. Hydrogen peroxide (compound 1), which has been used by the poultry industry, had a 70% reduction, and the water control produced a 10% reduction due to the rinsing effect. Several antimicrobials tested were more effective than hydrogen peroxide. More detailed studies will be required to adequately evaluate these antimicrobials.

Lipid damage during frozen storage of Gadiform species captured in different seasons

AbstractQuality loss of two gadiform fish species (blue whiting, Micromesistius poutassou; hake, Merluccius merluccius) during frozen storage (–30 and –10 °C; up to 12 months) was studied. For this, hydrolytic (formation of free fatty acids, FFA) and oxidative (conjugated dienes, peroxide and interaction compound formation) lipid damage were analysed. For both species, individual fishes captured in two different trials (May and November) were considered. Increasing (p &lt;0.05) lipid hydrolysis and oxidation (peroxide and interaction compound formation) were observed for all kinds of samples throughout the frozen storage. Interaction compound detection by fluorescence analysis showed the best correlation values with storage time. Some higher (p &lt;0.05) hydrolysis development could be observed in hake captured in May than in its counterpart from the November trial, while frozen blue whiting did not provide definite differences for FFA formation between both trials. Concerning peroxide formation, higher (p &lt;0.05) values were obtained for individual blue whiting and hake captured in November when compared to their corresponding May fish for both frozen storage conditions. Interaction compound formation was also found to be higher (p &lt;0.05) for November hake fish than for its counterpart captured in May, while blue whiting did not provide definite differences between trials.

The impact of destruction products of nonionogenic SAS on toxicity of their aqueous solutions and efficiency of biofiltration on activated carbon

The paper reports on the impact of products of chemical and biological destruction of nonionogenic SAS—nonylphenolethoxylates—on the toxicity of their aqueous solutions and on the efficiency of biofiltration on activated carbon in water treatment processes. It has been found that the method of activated chemiluminescence with Daphnia magna well characterizes the decrease in toxicity of solutions of nonionogenic SAS during their biofiltration, but to obtain correct data it is necessary to remove peroxide compounds from ozonized solutions. For determining the efficiency of biofiltration, it was proposed to use the value of the varying Gibbs free energy of absorption, which makes it possible to determine the change of the hydrophilic—lipophilic balance of matters as a result of their destruction on the surface of biologically activated carbon and completely correlates with the degree of removing nonionogenic SAS during biofiltration.

Molecular and cytological responses of Medicago truncatula to Erysiphe pisi

SUMMARY Powdery mildew is an economically important disease in a number of crop legumes; however, little is known about resistance to the disease in these species. To gain a better understanding of the genetics of resistance and plant responses to powdery mildew in legumes, we developed a pathosystem with Medicago truncatula and Erysiphe pisi. Screening accessions of M. truncatula identified genotypes that are highly susceptible, moderately resistant and highly resistant to the fungus. In the highly resistant genotype, fungal growth was arrested after appressorium development with no colony formation, while in the moderately resistant genotype a small number of colonies formed. Both resistant and moderately resistant genotypes produced hydrogen peroxide and fluorescent compounds at pathogen penetration sites, consistent with a hypersensitive response (HR), although the response was delayed in the moderately resistant genotype. Very little hydrogen peroxide or fluorescence was detected in the susceptible accession. Microarray analysis of E. pisi-induced early transcriptional changes detected 55 genes associated with the basal defence response that were similarly regulated in all three genotypes. These included pathogenesis-related genes and other genes involved in defence, signal transduction, senescence, cell wall metabolism and abiotic stress. Genes associated with the HR response included flavonoid pathway genes, and others involved in transport, transcription regulation and signal transduction. A total of 34 potentially novel unknown genes, including two legume-specific genes, were identified in both the basal response and the HR categories. Potential binding sites for two defence-related transcription regulators, Myb and Whirly, were identified in promoter regions of induced genes, and four novel motifs were found in promoter regions of genes repressed in the resistant interaction.